A cancer, which is a disease interrupting a function of normal cells due to immortalized cells, includes a lung cancer, a stomach cancer, a breast cancer, a large intestine cancer, etc., but can substantially be caused in all tissues.
The early cancer diagnosis is based on an external change of a biological tissue according to a growth of cancer cells.
In recent, however, a diagnosis and a detection of cancer have been attempted using a very small amount of biomolecules existing in a cell or a biological tissue, such as DNA, etc. (Korea Publication Patent No. 2008-0003472, International Publication Patent No. 2000-004149, U.S. Publication Patent 2004-586856, U.S. Publication Patent 2003-690880).
However, the most commonly used cancer diagnosis method may include a diagnosis using a tissue sample obtained through a biopsy or a diagnosis using images. However, the biopsy has disadvantages of giving patients an acute pain and incurring high costs as well as consuming much time until the diagnosis.
Also, in the case where patients actually develops cancer, there is a risk of inducing metastasis of cancer during the biopsy process and in the case of a region not capable of obtaining the tissue sample through the biopsy, the biopsy has a disadvantage in that the disease cannot be diagnosed until the doubted tissue is extracted through a surgical operation.
The diagnosis using images judges a cancer based on images obtained through X-ray, nuclear magnetic resonance imaging method using a contrast medium attached with disease target substance, nuclear imaging, etc. However, the diagnosis using the images has disadvantages in that it is a large possibility of a misdiagnosis according to a skill level of an operator or a reader and largely depends on precision of equipment obtaining an image.
Furthermore, since even the most precision equipment cannot detect a tumor of several mm or less, the diagnosis using the images has a disadvantage in that it is difficult to detect the tumor in the first stage of a disease. Also, since to obtain images, patients or persons who can have a disease is exposed to an electromagnetic wave inducing genomic mutation, the diagnosis using the images has disadvantages of an induction of another disease and a limitation of the frequency of the diagnosis through the images.
Whether a cancer of a digestive system is a disease or not is usually judged by observing its images with the naked eye using an endoscope; however, the process gives patients an acute pain and even though an abnormal symptom is found by observing the images with the naked eye, to accurately judge the diseases of a malignant/benign tumor, a polyp, etc., the biopsy must necessarily be performed. In particular, the large intestine cancer is a commonplace cancer within the third place in view of attack rate around the World and its curability largely depends on a progress stage of cancer.
In particular, when the large intestine cancer is found in the first stage through the early diagnosis, it has a very high cure rate. Therefore, above all thing, it is important to early find the large intestine cancer by the accurate early diagnosis, however, an abnormal symptom accompanied according to the progress of the cancer is insignificant. In most cases, it is common that the disease is recognized by a color change in excrements due to bleeding and although patients or persons who can have the disease are tested, it is common to observe the disease through the endoscope. Therefore, to accurately judge the disease, the biopsy must necessarily be performed.